WO2001084622A1

WO2001084622A1 - Wafer supporting device of semiconductor manufacturing device

Info

Publication number: WO2001084622A1
Application number: PCT/JP2001/003632
Authority: WO
Inventors: Yoji Takagi
Original assignee: Applied Materials Inc.
Priority date: 2000-04-28
Filing date: 2001-04-26
Publication date: 2001-11-08
Also published as: JP2001313329A; US20030015141A1; EP1289006A1; KR20020026480A

Abstract

A wafer supporting device, comprising a wafer supporting main body provided in the processing chamber of a semiconductor manufacturing device having a heat source on the upper and lower sides thereof, a lift part piece extending from the outside to the inside of the support area on the upper surface of the wafer support main body and having an inclined upper surface, an arc-shaped lift ring supporting the lift part piece, and a lift pin having an upper end part connected to the lift ring and moved vertically through a through-hole in the wafer supporting main body, characterized in that the through-hole is covered and closed substantially by the lift ring when the lift pin is lowered, whereby the nonuniformity of temperature distribution resulting from the through-hole can be eliminated.

Description

Specification

Device for supporting wafers in semiconductor manufacturing equipment

Technical field

The present invention relates to a wafer support device in a semiconductor manufacturing apparatus, and more particularly, to a wafer support device.

5 A means for moving the wafer up and down provided in the apparatus.

Background art

2. Description of the Related Art There is a semiconductor manufacturing apparatus called a single-wafer type that processes silicon wafers one by one. In this single-wafer semiconductor manufacturing apparatus, usually, a wafer supporting apparatus for horizontally supporting only one wafer is provided in the processing chamber.

10 A general wafer support device basically consists of a wafer support body on which a wafer is placed, a so-called susceptor. In addition, the wafer support device is provided with a lift mechanism for moving the wafer up and down with respect to the susceptor. A conventional general lift mechanism has a plurality of lift pins extending through the susceptor. A wafer is placed on the upper ends of these lift pins, and the lift pins are moved up and down.

L5 can be raised and lowered. With such a lift mechanism, it is possible to transfer a wafer carried on a blade of a transport robot onto a susceptor, or conversely, to transfer a wafer from a susceptor to a transfer robot. Become.

In the conventional wafer support apparatus as described above, when supporting the wafer, the lift pins are placed at a position lower than the upper surface of the susceptor. Therefore, when the lift bin is lifted to lift the wafer from the susceptor, the upper end of the lift bin may hit the rear surface of the wafer, and that portion may be damaged. Wafer backside flaws can adversely affect later processes. .

Also, when moving the wafer up and down, only the top of the lift pins support the back of the wafer! 5 The wafer is likely to be misaligned, and when it is dropped on the susceptor, it will protrude from the support area of the susceptor. There was a possibility. By the way, in an epitaxial growth apparatus which is one of the semiconductor manufacturing apparatuses, a heat source is arranged above and below the susceptor so that a wafer on the susceptor can be heated to a predetermined temperature. In this case, it is desirable that the temperature distribution on the entire surface of the susceptor be uniform, but a through hole for passing the lift pin is formed.

As a result, the temperature distribution on the surface of the susceptor tended to be uneven.

As a result of various studies conducted by the present inventor to solve the various problems as described above, the present inventors have found that a wafer support body having a support area for supporting a wafer on the upper surface thereof, and an outside of the wafer support body of the wafer support body. From the top to the inside of the support area, and has an inclined surface inclined downward and inward on the upper surface, and at a position lower than the upper surface of the wafer support body.

A wafer support device including a plurality of lift pieces that can move up and down between the L0 position and the upper position has been devised. Specifically, this configuration is as shown in FIGS.

8 and 9, reference numeral 1 denotes a wafer support for supporting the wafer W: a susceptor, and reference numeral 2 denotes a wafer support area. Reference numeral 3 denotes a lift piece.

L5. The lift piece 3 is formed as a component of the lift pin 4.

Since the position of the lift piece 3 and the upper surface thereof are inclined, the lift piece 3 does not come into contact with the back surface of the wafer W, but comes into contact only with the outer peripheral lower edge of the wafer W. Therefore, it is possible to prevent scratches on the back surface of the wafer. In addition, since the upper surface of the lift piece 3 is higher at the outer side, the displacement in the horizontal direction can be suppressed.

! 0 However, in a heat treatment apparatus such as an epitaxial growth apparatus, it is preferable that the lift piece 3 or the lift bin 4 be integrated with the susceptor 1 and be rotatable together with the susceptor 1. Since the evening 1 expands or contracts due to the temperature change, the lift bin 4 cannot be integrated with the susceptor 1 by a method such as hanging. That is, the thermal expansion of the susceptor 1 'The lift pin 4

! 5 If the piece 3 is significantly displaced, the lift piece 3 may not be able to support the lower peripheral edge of the wafer W. Therefore, as shown in Figs. It is inevitable to adopt a configuration in which the through hole 5 through which the air is passed is made relatively large, and the lift pin 4 is connected to the tip of the lift arm 6 that can move up and down. As a result, a gap is formed between the through hole 5 and the lift pin 4. This is considered to be the cause of uneven temperature distribution in the area 2 supported by the wafer.

Therefore, an object of the present invention is to provide a wafer support apparatus having a lift mechanism that can prevent scratches on the back surface of the wafer and misalignment of the wafer, and to make the temperature distribution uniform at least in a support area for supporting the wafer. It is to provide what can be done.

L0 Disclosure of the Invention

In order to achieve the above object, the present invention provides a wafer support body which is provided in a processing chamber of a semiconductor manufacturing apparatus having upper and lower portions and a heat source, and has on its upper surface a support error for supporting a wafer. A top surface having an inclined surface extending from the outside of the support area of the support body to the inside of the support area and inclined downward toward the inside; and a position below and above the top surface of the wafer support body. And a plurality of lift pieces that can move up and down with respect to the position, and an arc-shaped lift ring arranged outside the support area, wherein the lift pieces are formed on the inner peripheral edge of the lift ring. The lift ring, the upper end of which is connected to the lift ring, and a lift pin which is vertically moved through a through hole formed in the support body. Through hole is characterized and this has summer to be closed substantially covered by the lift ring.

This solves the problem of uneven temperature distribution due to the gap between the through hole and the lift pin.

Also, since the lift pins are restrained by the lift ring, the thermal expansion difference between the lift ring and the 55 wafer support body may cause the lift pins to strongly contact the inner wall surface of the through hole. It shall be a long hole extending in the radial direction of the holding body. Is valid.

In addition, a claw member is disposed on the lift ring so as to be vertically movable at a position adjacent to the lift piece, so that when the lift ring is lifted, the claw member is separated from the lift ring so that it can be further lifted. It is effective. In such a configuration, the riff

The horizontal movement of the wafer supported by the five-piece piece can be prevented by the claw member disposed at a higher position than the wafer.

Further, it is preferable that the cross-sectional shape of the upper surface of the lift piece along the circumferential direction of the support area be curved upward. Thereby, the contact between the lift piece and the wafer becomes a point contact.

L0 The above objects and other features and advantages of the present invention will become apparent to those skilled in the art by reading the following detailed description with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is an explanatory view schematically showing an epitaxy growth apparatus to which the wafer support apparatus of the present invention can be applied.

FIG. 2 is a plan view of the wafer supporting device according to the first embodiment of the present invention.

FIG. 3A is a cross-sectional view taken along the line III-III of FIG. 2, showing a state where the wafer is supported on a susceptor.

FIG. 3B is a cross-sectional view taken along the line III-III in FIG. 2, showing a state where the wafer is lifted from above the susceptor.

FIG. 4 is an arrow view along the line IV—IV in FIG. 3B.

FIG. 5 is a sectional view taken along line VV of FIG.

FIG. 6 is an end view along the line VI-VI of FIG.

FIG. 7A is a view showing a wafer supporting apparatus according to a second embodiment of the present invention, and is a cross-sectional view showing a state where wafers 5 are supported on a susceptor.

FIG. 7B is a cross-sectional view showing a state where the wafer is lifted from the susceptor. FIG. 8 is a cross-sectional view showing a birch tree obtained in the process of creating the present invention.

FIG. 9 is a partial plan view of the configuration of FIG. BEST MODE FOR CARRYING OUT THE INVENTION

5 Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 schematically shows an epitaxy growth apparatus as a semiconductor manufacturing apparatus on which a wafer support apparatus according to the present invention can be installed. The illustrated epitaxy growth apparatus 10 is a single wafer processing apparatus for processing silicon wafers (not shown in FIG. 1) one by one, and includes a processing chamber 12 made of quartz glass. Within 2

A wafer support device 14 is provided at L0. A processing gas inlet 16 is formed on the side of the processing chamber 12, and an exhaust port 18 is formed at a position facing the processing gas inlet 16. Further, a plurality of halogen lamps 20 are radially arranged in the upper region and the lower region of the processing chamber 12, respectively.

In the epitaxial growth apparatus 10 having the above structure, the wafer is supported by the wafer support apparatus 14, and then the halogen lamp 20 is turned on to heat the wafer. S i HC l ₃₎ Gasuya Axis Rorushiran _{_{(S i H 2 C l 2}} ) is introduced from the inlet 1 6 as a processing gas of the gas or the like, process gas layer along the surface of the wafer is heated to a predetermined temperature It flows in a flowing state, and a single crystal of silicon grows epitaxially on the wafer.

ίθ In such an epitaxial device 10, the wafer support device 14 according to the first embodiment of the present invention includes a susceptor 22 as a wafer support main body as shown in FIGS. . The susceptor 22 is a disc made of graphite material coated with silicon carbide, and is supported from the back side by a quartz glass support shaft 24 erected at the lower part of the processing chamber 12. Supported horizontally at points. Susep Evening

A circular recess 26 is formed on the upper surface of 15 22. The recess 26 is a support area for accommodating and supporting the wafer W. The center of the outer periphery of the bottom of the recess 26 An inclined surface 28 inclined downward toward the side is formed. Therefore, when the wafer W is placed at a predetermined position in the recess 26 of the susceptor 22, the wafer W is placed in a state where the lower peripheral edge (corner) of the wafer W is in contact with the inclined surface 28 of the outer periphery of the recess 26. Supported (see Figure 3A). In this support state, the upper surface of W and the support

5 The upper surface of the outer periphery is almost the same as the upper surface. This is to allow the processing gas introduced from the inlet 16 to flow while maintaining a laminar flow state.

A substantially arc-shaped (C-shaped) groove 30 is formed concentrically with the susceptor 22 on the outer peripheral portion of the susceptor 22. The arc angle of the groove 30 is preferably about 250 degrees. Within the groove 30, an arc-shaped or C-shaped lift ring that is substantially the same shape as the groove 30

L0 32 is arranged.

When the lift ring 32 is housed in the groove 30, the upper surface of the lift ring 32 and the upper surface of the outer peripheral portion of the susceptor 22 are dimensioned to be flush with each other for the same reason as described above. . At the inner peripheral edge of the lift ring 32, three lift pieces 36 are physically protruded. The three lift pieces 36 are provided at intervals of about 120 degrees.

L5 is preferred. Each lift piece 36 extends inward (toward the center of the susceptor 22), and its tip reaches the inner area of the recess 26. The susceptor 22 corresponding to the lift piece 36 is formed with a notch 38 having substantially the same shape as the lift piece 36 so that the lift ring 32 can be accommodated in the groove 30. So as not to interfere with

50 The upper surface of the lift piece 36 is one step lower than the upper surface of the lift ring 32, and when the lift ring 32 is accommodated in the groove 30, the bottom surface of the concave portion 26, at least the outer periphery It is located below the slope 28 of the part. Therefore, when supporting the wafer W on the susceptor 22, the wafer W does not come into contact with the lift piece 36. The upper surface of the lift piece 36 is inclined downward toward the center of the susceptor 22.

55 Furthermore, as can be understood from FIGS. 6 and 7, the upper surface of the lift piece 36 is formed as a curved surface that is upwardly convex in the circumferential direction of the susceptor 22. As shown in FIG. 1, the lift mechanism 34 according to this embodiment includes a lift tube 40 that can be moved up and down and that is arranged so as to surround the main shaft 24 a of the susceptor support shaft 24. Drive unit 42 for moving up and down 40, 3 lift arms 4 4 extending radially from lift tube 40, and bottom of groove 30 of susceptor 22

5 and a lift bin 48 suspended from a through hole 46 formed through. In such a configuration, when the drive unit 42 is controlled to lift the lift tube 40 and the lift arm 44, the lift bin 48 is pushed up at the tip of the lift arm 44, and as a result, the lift ring 3 2 The lifting bin 48 is suspended by a flange 49 formed at its upper end.

L0 The through hole 46 of the susceptor 22 is covered by a lift ring 32, as can be understood from FIGS. 2, 3A and 3B, and the lift pin 48 is lowered to lift the lift ring 32. The positions and dimensions of the through hole 46 and the lift ring 32 are determined so that the through hole 46 is substantially closed by the lift ring 32 when housed in the groove 30.

.5 The susceptor 22 is rotated in the horizontal direction so that the processing gas contacts the wafer W evenly during the process. For this reason, the susceptor support shaft 24 supporting the susceptor 22 is driven to rotate. However, the lift pins 48 are connected to the support arms 2 extending radially of the susceptor support shaft 24. 4 b through the through hole provided in b, so that it is integrated with the susceptor support shaft 24 and the susceptor 22

! 0 Rotated. For this reason, the susceptor support shaft

It is preferable that a ring plate 45 surrounding the main shaft 24 a of the 24 is attached, so that the lift bin 48 can be pushed up regardless of the position of the lift pin 48 in the rotation direction.

Also, the upper end of the lift pin 48 is formed in a concave portion formed on the lower surface of the lift ring 32.

: 5 and its movement is restrained by the lift ring 32.

In this manner, the lift bins 48 are formed by the lift arms 4 4 and the lift rings 3. Due to the difference in thermal expansion between the susceptor 22 and the lift arm and the lift ring 32, if the inner diameter of the through hole 46 is equal to the outer diameter of the lift pin 48, During the growth process, the side surfaces of the lift pins 48 may strongly contact the inner wall surfaces of the through holes 46. Therefore, in this embodiment, such a situation does not occur.

As shown in FIG. 4, the through hole 46 is a long hole extending in the radial direction of the susceptor 22 as shown in FIG. The major diameter of the through-hole 46 can be determined as appropriate, but it should be closed by the flange 49 of the lift pin 48 so that the processing gas does not flow downward from above through the through-hole 46 during the process. Is preferred.

When supporting the wafer W on the wafer support device 14 having such a configuration, first,

By operating the L0 transfer robot, the wafer W placed on the blade 50 of the transfer robot is placed immediately above the concave portion 26 of the susceptor 22. Next, the drive unit 42 of the lift mechanism 34 is controlled to raise the lift ring 32. At this time, since the blade 50 of the transfer robot is located at the open portion of the lift ring 32 (see FIG. 2), it does not hinder the lifting of the lift ring 32. Lift ring 3 2 is more than blade 50

L5 When the wafer W is raised to a higher position, the wafer W is transferred from the blade 50 to the lift piece 36 of the lift ring 32, and the wafer W is supported at three points (see FIG. 3B). Since the upper surface of the lift piece 36 is inclined downward toward the inside as described above, the portion where the lift piece 36 contacts is only the outer peripheral lower edge of the wafer W. The inclination of the lift piece 36 also serves to suppress the horizontal movement of the wafer W. Also each lift

! 0 Since the upper surface of the piece 36 is convexly curved, it contacts the wafer W at only one point.

In addition, since a step is formed between the lift piece 36 and the lift ring 32, the displacement of the wafer W is also prevented by this, but the wafer W may exceed the step for some reason. Therefore, it is preferable to provide a protrusion as shown by reference numeral 52 in FIGS. 3A and 3B.

! 5 If the wafer W is supported by the lift pieces 36 of the lift ring 32, the transfer robot blade 5 is moved from above the susceptor 22 to the outside of the processing chamber 12. To move the lifting ring 3 2 down. When the lift ring 32 is completely lowered into the groove 30, the lift piece 36 is located below the inclined surface 28 of the recess 26 of the susceptor 22, as shown in FIG. 3A. Therefore, the wafer W is supported on the inclined surface 28 of the concave portion 26. After this, the above-mentioned epitaxy growth process will be performed.

At this time, a gap is formed between the through hole 46 and the lift pin 48, but this gap is covered and closed by the lift ring 32 as described above. In this embodiment, the lift pins 48 are also closed by the flanges 49 of the lift pins 48. For this reason, the infrared L0 line from the halogen lamp 20, which is a heat source disposed at the lower part of the processing chamber 12, does not reach the upper surface of the susceptor 22 through this gap.

(Support area) This contributes to the uniformization of the temperature distribution of 26. The uniform temperature distribution contributes to the in-plane uniformity of the epitaxial growth.

When the wafer W is lifted from the susceptor 22 and transferred to the transport robot blade 50, it is easy to understand that if the lift mechanism 34 and the transport robot are operated in the reverse order to the above, L5 is sufficient. Let's do it.

7A and 7B show a wafer support device 114 according to a second embodiment of the present invention. In the second embodiment, the same or corresponding parts as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted. The lift mechanism 13 4 in the wafer support device 114 of the second embodiment has three claw portions ίθ material 133 on a C-shaped lift ring 132. At the position of the lift ring 1 32 where the claw member 133 is located, a concave portion where the claw member 133 is placed is formed, and the claw member 133 is fitted into this concave portion (FIG. 7). ) Has substantially the same shape as the lift ring 32 of the first embodiment. Further, the claw members 133 are arranged at positions adjacent to the lift pieces 36.

Therefore, the number of the claw members 133 is the same as the number of the lift pieces 3.

55 A through hole 60 is formed in the lift ring 13 2 at a position where the upper end of the lift pin 48 contacts. The through-hole 60 is formed by a flange formed at the upper end of the lift pin 48. The upper end is formed with an inward flange 64 so as to be able to receive 62 but to be lifted by a lift pin 48.

On the other hand, a hole 66 is formed in the claw member 133 to sit at a corresponding position. The inside diameter of the counterbore hole 66 is substantially the same as the outside diameter of the upper end of the lift pin 48. Change

5, a cylindrical projection 68 is formed on the lower surface surrounding the counterbore 66. The cylindrical projection 68 is adapted to be fitted into the through hole 60 of the lift ring 13 3 when the claw member 13 3 is placed on the lift ring 13 2.

In such a configuration, when the lift pins 48 are lowered, the pawl members 13 3 overlap the lift rings 13 2 as shown in FIG. 7A, and are substantially the same as FIG. 3A.

10 state. That is, the through hole 46 is covered and closed by the lift ring 13 2.

When the lift pin 48 is raised, the cylindrical projection 68 of the claw member 133 is first pushed up by the flange 62 of the lift pin 48. As a result, only the claw members 133 rise and separate from the lift rings 133. In this state, the lift member 3 6

The step between the upper surface of L5 and the upper surface of the claw members 133 becomes larger, and the effect of preventing the wafer W from moving in the horizontal direction increases. Therefore, it is not necessary to provide the protrusion 52 as shown in FIGS. 3A and 3B. When the lift pins are further raised, the flange portions 62 of the lift pins 48 come into contact with the lower surfaces of the flanges 64 of the through holes 60, and the claw members 133 and the lift rings 132 rise integrally. Other operations are the same as in the first embodiment.

The preferred embodiment of the present invention has been described above, but it is needless to say that the present invention is not limited to the above embodiment. For example, the semiconductor manufacturing apparatus of the above-described embodiment is an epitaxial growth apparatus, but the present invention is also applicable to an apparatus that performs another heat treatment, for example, a thermal CVD apparatus.

ί5

Industrial applicability As described above, according to the present invention, when a wafer is supported by a wafer support body such as a susceptor, or conversely, when the wafer is lifted from the wafer support body, the wafer is supported only by its outer peripheral lower edge. Since it is moved up and down, the back of the wafer is not scratched. Although the wafer supporting device of the present invention may damage the lower edge of the outer periphery of the wafer, the scratch at this portion does not cause any particular problem.

In addition, since the through hole for passing the lift bin is closed by the lift ring, it is possible to reduce the adverse effect of the through hole on the temperature distribution of the wafer support area, and to obtain a good process result. It contributes to improving the yield and performance of semiconductor devices.

Claims

The scope of the claims

1. A wafer support body provided in a processing chamber of a semiconductor manufacturing apparatus having upper and lower portions and a heat source and having a support area on a top surface for supporting a wafer, and a wafer support body of the wafer support body from outside the support area. Extending inside the support area,

5 A plurality of lifts having an inclined surface inclined downward toward the inside on an upper surface, and being vertically movable between a position below the upper surface and an upper position of the upper surface of the wafer support body. Pieces and

An arc-shaped lift ring disposed outside the support area, the lift ring L0 having the lift piece integrally formed on an inner peripheral edge of the lift ring;

A lift pin having an upper end connected to the lift ring and being vertically moved through a through hole formed in the support body;

With

The wafer support device wherein the through-hole is covered with the lift ring and is substantially closed at L5 when the lift pin is lowered.

2. The wafer supporting apparatus according to claim 1, further comprising a driving unit disposed below the lift pins for vertically moving the lift pins.

3. The wafer holding device according to claim 2, wherein the lift pins and the driving means are separable.

! 4 4. The wafer supporting apparatus according to claim 1, wherein the through hole is a long hole extending in a radial direction of the wafer supporting body.

5. The lift ring has a claw member that is vertically movable at a position adjacent to the lift piece, and when the lift ring is in a raised state, the claw member is the lift ring. A contractor that can be lifted separately from the

! 5 The wafer support device according to claim 1.

6. The cross-sectional shape of the upper surface of the lift piece along the circumferential direction of the support area is 3. The support device according to claim 1, wherein the support device is curved upwardly.

7. The wafer support apparatus according to claim 1, wherein the wafer support body is rotatable.

8. The wafer supporting device according to claim 2, wherein the semiconductor manufacturing device is an epitaxial growth device.